Not sure if anyone else is experiencing this, and I don't remember this happening on my Galaxy S3 when listening to music, but now that I have an S5, the Madsonic app seems to be downloading the album cover art and saving the files to my "Gallery"/photo album.

Under "Other Settings", there is a setting to hide the music from other apps. I believe on my S3, this was enabled, and until just now, it was disabled on the S5, so I enabled it. Testing this out now, but was wondering if the intention was to allow the album art to be saved to the photo album, or if it's a bug with the client software?